The present invention relates to an anti-fading agent. More specifically, the present invention relates to a anti-fading agent capable of advantageously inhibiting fading in colors of pigments caused by light, heat or the like, by comprising a specific oligosaccharide as an active ingredient. Further, the present invention relates to beverage and food products that are significantly suppressed in fading in colors by containing the anti-fading agent.
Conventionally, various synthetic pigments and natural pigments are used for coloring beverage and food products. In recent years, the natural pigments have been widely used, especially since safety of the synthetic pigments was called into question.
However, the natural pigments are comparatively unstable and tend to fade or change in colors with time as being affected by light, oxygen, heat and the like. Therefore the products such as beverage and food products, cosmetics and medicines by the natural pigments have problems that their commercial values would be reduced remarkably by suffering from the fading or change in colors. Since beverages bottled in clear container such as PET bottles are prevailed and products reduced in degree of coloring are preferred particularly in recent days, there is a demand for immediately developing a method for advantageously suppressing or preventing the pigments from fading in colors.
An object of the present invention is to provide an anti-fading agent capable of advantageously suppressing fading in colors of pigments. Another object of the present invention is to provide an anti-fading agent effective against fading in colors caused particularly by heat and light.
Another object of the invention is to provide colored beverage and food products which are significantly suppressed in fading in colors of pigments by containing the anti-fading agent.
Note that the word xe2x80x9cfading in colorsxe2x80x9d used herein includes reduction in coloring strength (of the degree of coloring) and change in colors of pigments.
The inventors have carried out an extensive research to achieve the above objects, and found specific oligosaccharides such as nigerooligosaccharide, maltooligosaccharide and panose exert an excellent suppressing or inhibitory action on fading in colors of various pigments, especially of natural pigments. The inventors have studied further based on the findings and succeeded in improving the above-described anti-fading action of the oligosaccharides by using them together with an antioxidant, to thereby accomplish the present invention.
The present invention provides an anti-fading agent for pigments, comprising at least one oligosaccharide-selected from the group consisting of nigerooligosaccharide, maltooligosaccharide and panose as an active ingredient.
Further, the present invention provides an anti-fading agent for pigments, comprising at least one oligosaccharide selected from the group consisting of nigerooligosaccharide, maltooligosaccharide and panose and an antioxidant as active ingredients.
In addition, in the anti-fading agent of the present invention, the following embodiments may be included.
(1) An anti-fading agent for a pigment wherein the pigment is a natural pigment.
(2) An anti-fading agent for a pigment wherein the pigment is at least one natural pigment selected from the group consisting of quinoid-based pigments, anthocyanin-based pigments, flavonoid-based pigments, azaphilone-based pigments, betacyanin-based pigments, Gardenia blue pigment and Gardenia red pigment.
(3) An anti-fading agent for a pigment, wherein the pigment is an anthocyanin-based pigment.
(4) An anti-fading agent for a pigment, wherein the pigment is a carotinoid-based pigment or a flavonoid-based pigment.
(5) An anti-fading agent for a pigment, which comprises at least one antioxidant selected from the group consisting of Chinese bayberry extract, rutin extract, coffee bean extract, rosemary extract, enzymatically modified rutin and enzymatically modified isoquercitrin.
Further, the present invention provides a pigment-containing colored substance which is suppressed in fading in colors by containing above-described anti-fading agent comprising the oligosaccharide or the oligosaccharide and antioxidant as active ingredients. The following embodiments may be included in the pigment-containing colored substance.
(a) A pigment-containing colored substance, wherein the colored substance is a beverage and food product.
(b) A pigment-containing colored substance, wherein the pigment is a natural pigment.
(c) A pigment-containing colored substance, wherein the pigment is at least one natural pigment selected from the group consisting of quinoid-based pigments, anthocyanin-based pigments, flavonoid-based pigments, azaphilone-based pigments, betacyanin-based pigments, Gardenia Blue pigment and Gardenia Red pigment.
(d) A pigment-containing colored substance, wherein the pigment is an anthocyanin-based pigment.
(e) A pigment-containing colored substance, wherein the pigment is a carotinoid-based pigment or a flavonoid-based pigment.
(f) A pigment-containing colored substance which comprises the anti-fading agent in an amount of at least 0.1 parts by weight calculated as an oligosaccharide content.
(g) A pigment-containing colored substance which comprises 0.5-100 parts by weight of the antioxidant based on 100 parts by weight of the oligosaccharide contained therein.
(h) A pigment-containing colored substance, which comprises at least one antioxidant selected from the group consisting of Chinese bayberry extract, rutin extract, coffee bean extract, rosemary extract, enzymatically modified rutin and enzymatically modified isoquercitrin.
Further, the present invention provides a method for inhibiting fading in colors of the pigment, wherein above-described anti-fading agent comprising as active ingredients the oligosaccharide or the oligosaccharide and antioxidant is added to a pigment. The following embodiments may be included in the method for inhibiting fading in colors.
(i) A method for inhibiting fading in colors of the pigment, wherein the pigment is a natural pigment.
(ii) A method for inhibiting fading in colors of the pigment, wherein the pigment is at last one natural pigment selected from the group consisting of quinoid-based pigments, anthocyanin-based pigments, flavonoid-based pigments, azaphilone-based pigments, betacyanin-based pigments, Gardenia Blue pigment and Gardenia Red pigment.
(iii) A method for inhibiting fading in colors of the pigment, wherein the pigment is an anthocyanin-based pigment.
(iv) A method for inhibiting fading in colors of the pigment, wherein the pigment is a carotinoid-based pigment or a flavonoid-based pigment.
(v) A method for inhibiting fading in colors of the pigment, wherein the fading in colors is caused by light irradiation.
(vi) A method for inhibiting fading in colors of the pigment, wherein the fading in colors is caused by heat-treatment.